I had the same idea...

about seven years ago. Got two from a guy that had been sitting in his back yard for several years. I was gonna make a bad ass go kart. Rings were siezed on the pistons. Tried soaking them in everything over a couple months trying to get them to come loose. Never could find pistons for it. Ended up giving up. If you need a gasket set and/or carb kits I've got 'em. Good luck.